1) Field of the Invention
The present invention relates generally to tillage equipment and, more specifically, to a disk scraper system for a harrow or other implement having a plurality of disks.
2) Related Art
Typically, disk harrows include a main frame with several disk gang assemblies suspended for limited flexibility with respect to each other and the main frame. Each gang assembly comprises a plurality of equally spaced disks mounted on an axle for rotation about a common axis. The axle is supported at opposite ends by C-shaped spring elements to allow the disk gangs to flex with the contour of the landscape as the implement is drawn by a tractor. Depending on soil and crop conditions, an accumulation of soil and residue will adhere to the disks and adversely affect disk operation. To eliminate the accumulation of soil and residue, a disk scraper which is often mounted from the main frame is biased by a spring into contact with the surface of the disk. As the disk rotates, the scraper continuously removes the soil/residue accumulations.
During disk operation in the field, the disk gangs flex with ground contour changes and oscillate laterally as different soils act upon the disk surfaces. When the lateral oscillations occur, the disk mounting arrangement causes the disk scraper pressure against the disks to increase or decrease depending on the magnitude and direction of the oscillation. Since the disk scrapers and biasing means are mounted from the main frame and the disk gangs move with respect to said frame, disk scraper pressure can vary considerably. As the disk gang shifts laterally away from the scraper, biasing force from the spring is reduced resulting in a non-clean disk surface. As the disk gang shifts laterally the opposite direction, an excessive force is applied to the disk surface. The force is usually more than necessary to scrape the disk clean and results in excessive wear and added draft requirements. Also, as the disk gang shifts laterally away from or toward the scrapers, the preferred angular relationship between the scraper and blade is not maintained.
Attempts to address disk scraper problems include mounting the scrapers directly to the disk gang assembly so the scrapers move with the assembly. However, such a design requires mounting brackets and hardware connected between the disk scrapers and the disk gang, thereby hindering trash and soil flow and providing additional surfaces where material can accumulate. Additionally, in current disk scraper mounting designs, changing the bias of the scraper requires changing springs or increasing or decreasing the number of springs. These changes can be very time consuming and require additional parts and expense.